Improvement in padlocks



W. F. HOFMANN. Padlock.

No. 218,026. Patented July 29, |879.

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lypni UNITED STATES PATENT FEICE` WILLIAM F. HOFMANN, OF PHILADELPHIA,PENNSYLVANIA, ASSIGNOR OF ONE-HALF HIS RIGHT TO CHARLES M. GHRISKEY, 0FSAME PLAGE.

IMPROVEMENT IN PADLOCKS.

Specification forming part of Letters Patent No. 218,026, dated July 29,1879; application tiled May '7, 1879.

To all whom it may concern: I

Be it known that I, WILLIAM F. HOFMANN, of Philadelphia, Pennsylvania,have invented a new and useful Improvement in Padlocks, of which thefollowing is a specification.

My invention relates to au improvement in that class of padlocks inwhich a bolt works across a slot in the case; the main object of myinvention being to provide such a lock with a simple device forretaining and releasing the bolt, and a further object being to providecompact mechanism for operating the bolt by means of a key.

In the accompanying drawings, Figure 1 is a general perspective Viewshowing the exterior of the lock and a staple adapted to the same; Figs.2 and 3, views of the lock from which the front plate has been removed,and showing the operating parts in different positions; Fig. 4, atransverse section of the lock on the line l 2 of Fig. 2; Fig. 5, a viewof a part of the case from which the works have been removed, and Fig.6, a perspective view of detached portions of the works.

The case is, in the present instance, of hexagonal form and has oppositeiiat sides. A slot, a, extends entirely through the lock to admit astaple, b, and there'is within the lock a bolt, B, which can be sooperated that a portion of it will extend across the slot at rightangles to the same and through the staple contained within the slot, ormay be withdrawn into the case, according to the direction in which thekey is turned, as explained hereinafter.

I may remark here that it is not essential to make the case hexagonal,although I prefer that form; nor is it necessary in all cases for theslot to extend entirely7 through the case, as the latter may be made sothick that a recess in place of the slot may be made deep enough in oneside of the case to receive the staple and permit it to assume a properposition for receiving the bolt. In place of the staple a simple platewith a hole for the bolt may be admitted to the slot.

The case consists of two hexagonal plates, A A', and interveninghexagonal rib; or, what is preferable, the case may consist of twoplates, one of them being a plain fiat piece of metal, and the other(marked A in Fig. 5,)

having a continuous edge, c, cast on it, ribs f fl f2 being also cast onthe plate on three sides of the slot a.

B is the bolt, the upper rounded portion, h, of which is arranged toslide in a hole in the lower rib, f2, of the case, and it can also passinto a corresponding hole in the upper rib,f, the bolt being furtherguided by a rib, i, in the case, which rib is adapted to 'a slot in theback of the bolt.

To a pin,j, projecting from the case is pivoted a curved arm, D, the endot' which passes through a slot in the bolt.

E is a sliding trigger-plate, the upper portion, k, of which litsbetween and is guided by the ribs f f2, at the upper and lower edge ofthe slot a, the said portion 7c of the plate serving, in fact, to closeone end of the slot c, and the lower portion of the plate being slottedat y to receive a guiding-stud projecting from the plate A of the case.

A spring, p, bears against the back of the plate and tends to force ittoward the bolt, which is retained in depressed condition by the lowercorner of the plate, as shown in Fig. 3.

After adjusting the lock to a staple so that the latter shall occupy aposition in the slot, and then pushing the lock in the direction of thearrow, Fig. 3, the upper portion, k, of the plate will be brought intocontact with the staple and will yield to the latter, thereby releasingthe bolt B, which, owing to the spring d, will be shot upward, and itsupper rounded portion will be projected across the slot a and into thehole in the rib f2.

F is' the key, having two projections, w and w', the latter having alip, c. When this key is in the act of depressing the bolt, its end woccupies a position in a depression in the pin j, to which the arm D ispivoted, and the lip c of the projection w bears against a projection,t, of the arm, while the other projection, fw, of the key bears againstthe opposite projection, t', so that on turning the key in the directionof the arrow, Fig. 2, the arm D will depress the bolt until the shoulderu on the same passes the lower corner of the plate E, when the latterwill be projected forward by its spring and resume its duty of retainingthe bolt in its depressed condition. But

before the key can reach a position which Will enable it. to turn thearm D, it must pass the tumbler H,and this tumbler must be moved back bythe key before the bolt can be depressed.

The tumbler is so guided in the case that it can be moved to and fro atright angles, or thereabout, to the direction in which the bolt moves.When the bolt is raised, as in Fig. 2, the tumbler has been moved by itsspringg toward the bolt, Vand a projection, 2,011 the tumbler is beneatha shoulder on the bolt, so that the latter cannot be depressed by anyforcing action on that portion ot' the bolt which is more or lessexposed at the slot a; but the rst action of the lip v of the key outurning the latter is to bear against the tumbler at the point 3, Fig.2, and to move the tumbler back, thereby permitting` the lipvof the keyto pass between the tumbler and the hub of the arm D until it reachesthe projection t of the said arm, when the latter can be turned by thekey and the bolt can be depressed, for in turning the key the latter hadmoved back the tumbler to the position Fig. 3, thereby releasing thebolt and permitting it to be depressed.

The portion f the tulnbler against which the key acts has a recess foradmitting a projection on the lip r of the key, and there may be anumber of these projections on the key to correspond with a recess onthe tumbler; or

the latter may have a number of projections adapted to Wards in the key,thereby increasing the difculty of picking the lock; or there may be aseries of thin tumblers, placed one against the other,in place of onethick tumbler.

I claim as my invention- 1. The combination of the lock-case having aslot, a, and bolt B, with a spring-trigger, E, part of which occupies aposition in said slot, and which serves to retain and release the bolt,all substantially as set forth.

2. The combination of the slotted lock-case, the slotted sliding bolt B,adapted thereto, and the curved arm I), pivoted to the case, adapted tothe slot in the bolt B, and having a projection or projections and arecess, j, adapted to a key, all as set forth.

3. The combination of the slotted lock-case, the slotted sliding bolt B,adapted thereto, the curved operating-arm D, constructed for operationby the key, and the sliding tumbler or tumblers H, arranged in respectto the arm D, as set forth.

In testimony whereofI have signed my name to this specification in thepresence of two subscribing witnesses.

